The majority of building toys fall into three categories of full scale construction: masonry, wood, and steel. The success of Lego as the masonry, Lincoln-logs as the wood, and Erector-set as the steel system has influenced similar designs over the years. The above mentioned products and those that fall into similar categories lack a piece that can efficiently define a volume of space. Many bricks or logs need to be stacked to make a wall for a room, and many girders need to be assembled to define the skeletal perimeter of a space. A precast concrete slab can serve as a wall or as a floor slab for defining space in construction. Precast concrete as a modern building medium offers the compressive strength of masonry and the tensile strength of steel. As well, precast concrete exceeds the longevity of wood. Precast concrete has a counterpart of injection molded plastic in the miniature toy world. Both materials have a high strength to surface area ratio.
Several products and building block inventions have planar pieces that are comprised of interlocking slabs. Typically the toys have square pieces that are notched so that they can be joined with five other identical pieces to form a hollow cube. The following three inventions all have this characteristic: Toy Construction Block U.S. Pat. No. 1,894,061, Toy Construction Element U.S. Pat. No. 2,558,591, and Cuboidal Structure U.S. Pat. No. 3,924,376. The three above mentioned inventions can effectively form cubes, but in each case, the edge of the finished cube has a smooth interlocking fit that will not allow an additional piece to join on any side. The above mentioned inventions have pieces that can be joined two dimensionally indefinitely to make long square tubes, or they can be joined at right angles to form indefinite zigzag stairs. The invention here in described has the unique asymmetrical notched edge that enables one to make a cube that can then have two pieces join at each cube edge, making a total of up to 24 additional connecting pieces. The resulting four way connections give this invention the optimal construction flexibility for building three dimensionally. The invention enables a builder or a toy enthusiast to create simple volumes like a cube that can be embellished on increasingly more sophisticated levels. This invention enables the architect or engineer to design diverse large scale projects with a repeated modular system.
Precast concrete beams and columns are effectively used in construction because like the precast slab they are strong in both compression and tension. This invention includes a combination column and beam with ends that fit into the notch system of the square piece or two engaged pieces. The column end is designed to fit into half of the opening created by the slab piece so that a second column can fit into the same opening in the slab piece from the other side, see FIG. 5. This allows for a continual stacking of columns that intermittently support floor slabs at each level. The column piece, described in U.S. Pat. No. 1,562,006 Educational Building Construction Set, has protrusions that fill the entire cavity of the second piece and thus restrict continued construction from the opposite side. The one half notched pieces, described in U.S. Pat. No. 4,270,304 Flush-Fitting Toy Building Blocks, do not have a protrusion that can fit into secondary pieces to build vertically as columns.